Measurement of cross-reactive properties of adriamycin derivatives by the inhibition enzyme-linked immunosorbent assay for adriamycin.

An inhibition enzyme-linked immunosorbent assay (Inhibition ELISA) system for adriamycin has been established. In this assay system, polyclonal anti-adriamycin antiserum produced in rabbits was used. The assay system showed sensitivity for adriamycin in the range of 0.1-2.5 micrograms/ml (0.53-4.23 nmoles per ml). This assay system was applied to analyze the cross-reactive properties of substances with chemical structures similar to that of adriamycin. The cross-reactive properties of six kinds of adriamycin derivatives (Epirubicin, Daunorubicin, Pirarubicin, Aclarubicin, SM-5887 and MX-2) against anti-adriamycin antiserum were measured. The cross-reactive properties of each derivative against the antiserum differed in accordance with the differences in the position of their functional groups attached to the anthracyclic ring. The antiserum recognized the -epi type of -OH group at the -4' position on sugar chains as well as number of sugar chains attached to the anthracyclic ring, and it also recognized the glycoloyl or acetyl and/or ethyl group at position 9 on the anthracyclic ring. With this assay system, the antigenic determinant sites of the anticancer drugs were inferred.